Building an AI Dating Assistant with Flutter and Go
In today’s fast-paced world, finding the right connection can feel like searching for a needle in a haystack. What if technology could lend a hand? In this blog post, we’ll embark on an exciting journey to build a scalable AI dating assistant using the power of Flutter for our beautiful user interface and the robust performance of Golang for our backend.
This guide is designed for developers with a beginner’s understanding of both Flutter and Golang. We’ll break down the process step-by-step, providing code snippets and explanations along the way.
Why Flutter and Golang? A Match Made in Tech Heaven
- Flutter: Known for its rapid development, expressive UI toolkit, and cross-platform capabilities, Flutter is perfect for creating a delightful and engaging user experience for our dating app.
- Golang: Google’s Go programming language excels in building scalable and efficient backend systems. Its concurrency features and performance make it ideal for handling a growing user base and complex AI logic.
Our AI Dating Assistant: A High-Level Overview
Our assistant will have the following basic functionalities:
- User Registration and Profile Creation: Users can create profiles with their interests, preferences, and photos.
- AI-Powered Matching: The backend will use a simplified AI algorithm to suggest potential matches based on user profiles.
- Viewing Potential Matches: Users can browse through suggested profiles.
Let’s Get Started!
We’ll divide our development into two main parts: the backend (Golang) and the frontend (Flutter).
Part 1: Building the Backend with Golang
Our Golang backend will handle user data, the AI matching logic, and expose an API for our Flutter app to consume.
Step 1: Setting up the Go Environment
Make sure you have Go installed on your system. You can download it from https://go.dev/dl/.
Step 2: Creating the Project Structure
Create a new directory for your Go backend and initialize a Go module:
Bash
mkdir dating-assistant-backend
cd dating-assistant-backend
go mod init dating-assistant
Step 3: Defining the User Model
Create a file named models.go to define our user structure:
Go
// models.go
package main
type User struct {
ID int `json:"id"`
Name string `json:"name"`
Age int `json:"age"`
Interestsstring `json:"interests"`
Preferences Preferences `json:"preferences"`
}
type Preferences struct {
AgeRange int `json:"age_range"`
Interestsstring `json:"interests"`
}
Step 4: Implementing a Simple In-Memory Data Store (for this example)
For simplicity, we’ll use an in-memory map to store user data. In a real-world application, you’d use a database like PostgreSQL or MongoDB. Create a file named main.go:
Go
// main.go
package main
import (
"encoding/json"
"fmt"
"log"
"net/http"
"strconv"
"github.com/gorilla/mux" // Using a popular router for easier API handling
)
var users = make(map[int]*User)
var nextUserID = 1
func main() {
router := mux.NewRouter()
// Define API endpoints
router.HandleFunc("/users", createUser).Methods("POST")
router.HandleFunc("/users/{id}", getUser).Methods("GET")
router.HandleFunc("/matches/{id}", getMatches).Methods("GET")
fmt.Println("Server listening on port 8080...")
log.Fatal(http.ListenAndServe(":8080", router))
}
// createUser handles the creation of new users
func createUser(w http.ResponseWriter, r *http.Request) {
var user User
err := json.NewDecoder(r.Body).Decode(&user)
if err != nil {
http.Error(w, "Invalid request body", http.StatusBadRequest)
return
}
user.ID = nextUserID
users[nextUserID] = &user
nextUserID++
w.WriteHeader(http.StatusCreated)
json.NewEncoder(w).Encode(user)
}
// getUser retrieves a specific user by ID
func getUser(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
idStr := vars["id"]
id, err := strconv.Atoi(idStr)
if err != nil {
http.Error(w, "Invalid user ID", http.StatusBadRequest)
return
}
user, ok := users[id]
if !ok {
http.Error(w, "User not found", http.StatusNotFound)
return
}
w.WriteHeader(http.StatusOK)
json.NewEncoder(w).Encode(user)
}
// getMatches retrieves potential matches for a given user ID (simplified AI logic)
func getMatches(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
userIDStr := vars["id"]
userID, err := strconv.Atoi(userIDStr)
if err != nil {
http.Error(w, "Invalid user ID", http.StatusBadRequest)
return
}
currentUser, ok := users[userID]
if !ok {
http.Error(w, "User not found", http.StatusNotFound)
return
}
var matches*User
for _, potentialMatch := range users {
if potentialMatch.ID != currentUser.ID && isMatch(currentUser, potentialMatch) {
matches = append(matches, potentialMatch)
}
}
w.WriteHeader(http.StatusOK)
json.NewEncoder(w).Encode(matches)
}
// isMatch implements a very basic matching logic
func isMatch(user1 *User, user2 *User) bool {
// Check age preference
if user2.Age < user1.Preferences.AgeRange[0] || user2.Age > user1.Preferences.AgeRange[1] {
return false
}
if user1.Age < user2.Preferences.AgeRange[0] || user1.Age > user2.Preferences.AgeRange[1] {
return false
}
// Check for common interests (at least one common interest)
hasCommonInterest := false
for _, interest1 := range user1.Interests {
for _, interest2 := range user2.Preferences.Interests {
if interest1 == interest2 {
hasCommonInterest = true
break
}
}
if hasCommonInterest {
break
}
}
if !hasCommonInterest {
return false
}
hasCommonInterest = false
for _, interest2 := range user2.Interests {
for _, interest1 := range user1.Preferences.Interests {
if interest2 == interest1 {
hasCommonInterest = true
break
}
}
if hasCommonInterest {
break
}
}
if !hasCommonInterest {
return false
}
return true
}
Step 5: Running the Backend
Open your terminal in the1 dating-assistant-backend directory and run:
Bash
go get github.com/gorilla/mux
go run main.go
Your Golang backend should now be running on http://localhost:8080.
Part 2: Building the Frontend with Flutter
Now, let’s create the user interface for our dating assistant using Flutter.
Step 1: Setting up the Flutter Environment
Make sure you have Flutter installed2 on your system. You can follow the installation guide at https://flutter.dev/docs/get-started/install.
Step 2: Creating a New Flutter Project
Open your terminal and run:
Bash
flutter create dating_assistant_app
cd dating_assistant_app
Step 3: Adding the http Package
We’ll need the http package to make API calls to our Golang backend. Open your pubspec.yaml file and add http under dependencies:
YAML
dependencies:
flutter:
sdk: flutter
http: ^1.2.1 # Use the latest version
Then, run flutter pub get in your terminal.
Step 4: Creating the User Model (Dart)
Create a models directory and a file named user.dart:
Dart
// lib/models/user.dart
class User {
final int id;
final String name;
final int age;
final List<String> interests;
final Preferences preferences;
User({
required this.id,
required this.name,
required this.age,
required this.interests,
required this.preferences,
});
factory User.fromJson(Map<String, dynamic> json) {
return User(
id: json['id'],
name: json['name'],
age: json['age'],
interests: List<String>.from(json['interests']),
preferences: Preferences.fromJson(json['preferences']),
);
}
}
class Preferences {
final List<int> ageRange;
final List<String> interests;
Preferences({
required this.ageRange,
required this.interests,
});
factory Preferences.fromJson(Map<String, dynamic> json) {
return Preferences(
ageRange: List<int>.from(json['age_range']),
interests: List<String>.from(json['interests']),
);
}
}
Step 5: Implementing the Registration Screen
Create a screens directory and a file named registration_screen.dart:
Dart
// lib/screens/registration_screen.dart
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
class RegistrationScreen extends StatefulWidget {
@override
_RegistrationScreenState createState() => _RegistrationScreenState();
}
class _RegistrationScreenState extends State<RegistrationScreen> {
final _formKey = GlobalKey<FormState>();
final _nameController = TextEditingController();
final _ageController = TextEditingController();
final _interestsController = TextEditingController();
Future<void> _registerUser() async {
if (_formKey.currentState!.validate()) {
final response = await http.post(
Uri.parse('http://localhost:8080/users'),
headers: <String, String>{
'Content-Type': 'application/json; charset=UTF-8',
},
body: jsonEncode(<String, dynamic>{
'name': _nameController.text,
'age': int.parse(_ageController.text),
'interests': _interestsController.text.split(','),
'preferences': {
'age_range': [18, 35], // Default preferences for simplicity
'interests':,
},
}),
);
if (response.statusCode == 201) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Registration successful! User ID: ${jsonDecode(response.body)['id']}')),
);
// Navigate to the next screen or clear the form
} else {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Registration failed: ${response.body}')),
);
}
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Register')),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Form(
key: _formKey,
child: Column(
children: <Widget>[
TextFormField(
controller: _nameController,
decoration: InputDecoration(labelText: 'Name'),
validator: (value) {
if (value == null || value.isEmpty) {
return 'Please enter your name';
}
return null;
},
),
TextFormField(
controller: _ageController,
keyboardType: TextInputType.number,
decoration: InputDecoration(labelText: 'Age'),
validator: (value) {
if (value == null || value.isEmpty) {
return 'Please enter your age';
}
if (int.tryParse(value) == null) {
return 'Please enter a valid age';
}
return null;
},
),
TextFormField(
controller: _interestsController,
decoration: InputDecoration(labelText: 'Interests (comma-separated)'),
validator: (value) {
if (value == null || value.isEmpty) {
return 'Please enter your interests';
}
return null;
},
),
SizedBox(height: 20),
ElevatedButton(
onPressed: _registerUser,
child: Text('Register'),
),
],
),
),
),
);
}
}
Step 6: Implementing the Match List Screen
Create a file named match_list_screen.dart in the screens directory:
Dart
// lib/screens/match_list_screen.dart
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import '../models/user.dart';
class MatchListScreen extends StatefulWidget {
final int userId;
MatchListScreen({required this.userId});
@override
_MatchListScreenState createState() => _MatchListScreenState();
}
class _MatchListScreenState extends State<MatchListScreen> {
List<User> _matches =;
bool _loading = true;
@override
void initState() {
super.initState();
_fetchMatches();
}
Future<void> _fetchMatches() async {
final response = await http.get(
Uri.parse('http://localhost:8080/matches/${widget.userId}'),
);
if (response.statusCode == 200) {
final List<dynamic> data = jsonDecode(response.body);
setState(() {
_matches = data.map((json) => User.fromJson(json)).toList();
_loading = false;
});
} else {
setState(() {
_loading = false;
});
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text('Failed to load matches: ${response.body}')),
);
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Potential Matches')),
body: _loading
? Center(child: CircularProgressIndicator())
: _matches.isEmpty
? Center(child: Text('No matches found yet!'))
: ListView.builder(
itemCount: _matches.length,
itemBuilder: (context, index) {
final match = _matches[index];
return Card(
margin: EdgeInsets.all(8.0),
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text('Name: ${match.name}', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
Text('Age: ${match.age}'),
Text('Interests: ${match.interests.join(', ')}'),
// Add more details as needed
],
),
),
);
},
),
);
}
}
Step 7: Connecting the Screens in main.dart
Modify your lib/main.dart3 file to include the registration screen and a way to navigate to the match list (for simplicity, we’ll navigate directly after registration in this example).
Dart
// lib/main.dart
import 'package:flutter/material.dart';
import 'screens/registration_screen.dart';
import 'screens/match_list_screen.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'AI Dating Assistant',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: RegistrationScreen(), // Start with the registration screen
);
}
}
Step 8: Running the Flutter App
Open your terminal in the dating_assistant_app directory and run:
Bash
flutter run
This will build and run your Flutter app on your connected device or emulator.
Part 3: Scalability Considerations
While our example is basic, let’s briefly discuss how Flutter and Golang contribute to building scalable applications:
- Golang’s Concurrency: Go’s built-in concurrency features (goroutines and channels) make it efficient at handling multiple requests simultaneously, crucial for a growing user base.
- Efficient Rendering in Flutter: Flutter’s Skia rendering engine provides high performance and smooth animations, ensuring a good user experience even with complex UIs.
- Microservices Architecture: For larger applications, you could further enhance scalability by breaking down the backend into smaller, independent services (microservices) built with Golang.
- Database Choices: Selecting a scalable database like PostgreSQL with proper indexing and connection pooling is essential4 for handling large amounts of data.